Identification and Characterization of the Neutralization Epitope(s) of the Hepatitis E Virus

Meng, Jingjing; Xing, Dan; Chang, Joy; Lopareva, Elena N.; Pillot, J.; Fields, Howard A.; Khudyakov, Yury

doi:10.1006/viro.2001.1093

Cited by 151 publications

(107 citation statements)

References 41 publications

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“…HEV-CP is a key antigen that stimulates the host immune response, and 6 antigenic domains have been identified (11). One neutralization site has been mapped to the polypeptide region between amino acids 452 and 617 (12).…”

mentioning

confidence: 99%

Structure of the hepatitis E virus-like particle suggests mechanisms for virus assembly and receptor binding

Guu

Liu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

223

247

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Hepatitis E virus (HEV), a small, non-enveloped RNA virus in the familyHepeviridae, is associated with endemic and epidemic acute viral hepatitis in developing countries. Our 3.5-Å structure of a HEV-like particle (VLP) shows that each capsid protein contains 3 linear domains that form distinct structural elements: S, the continuous capsid; P1, 3-fold protrusions; and P2, 2-fold spikes. The S domain adopts a jelly-roll fold commonly observed in small RNA viruses. The P1 and P2 domains both adopt ␤-barrel folds. Each domain possesses a potential polysaccharide-binding site that may function in cell-receptor binding. Sugar binding to P1 at the capsid protein interface may lead to capsid disassembly and cell entry. Structural modeling indicates that native T ‫؍‬ 3 capsid contains flat dimers, with less curvature than those of T ‫؍‬ 1 VLP. Our findings significantly advance the understanding of HEV molecular biology and have application to the development of vaccines and antiviral medications.capsid ͉ HEV V iral hepatitis is principally caused by 5 distinct viruses named hepatitis A-E. Despite their similar names, the 5 viruses are unrelated, and they have totally different genome structures with distinct replication mechanisms. Hepatitis E virus (HEV) is responsible for endemic hepatitis as well as sporadic epidemics of acute, enterically transmitted hepatitis in the developing world, including parts of Asia, the Middle East, Africa, and Mexico (1, 2). HEV accounts for more than 50% of acute viral hepatitides in young adults in these regions, with a case fatality of 1-2% in regular patients and up to 20% in pregnant women.Given the lack of a robust cell culture system, and because HEV is not closely related to any other well-characterized virus, little is known about the molecular biology of HEV or its strategy for replication (1). HEV is a small, non-enveloped virus with a 7.2 kb, positive-sense RNA genome. Its genomic RNA is polyadenylated and contains 3 ORFs. Located near the 5Ј-end, ORF1 encodes a non-structural polyprotein with multiple functional domains, including those for methyltransferase, protease, helicase, and polymerase. The viral capsid protein (CP) is encoded by ORF2 near the 3Ј-end. ORF3, which partially overlaps with the other 2 ORFs, codes for an immunogenic protein of unknown function. HEV was originally classified in the Caliciviridae family because of its structural similarity to other caliciviruses; however, it is now the sole member of the Hepeviridae family. The genomic RNA of HEV exhibits several distinct features compared to the genomic RNA of caliciviruses, including a methylated cap at the 5Ј-end and an ORF1 with functional domains arranged in a different order (1, 3).Previous studies of HEV assembly have primarily focused on the overexpression of viral proteins. The ORF2 capsid protein, HEV-CP, contains a total of 660 amino acid residues. At the HEV-CP N terminus is a signal peptide followed by an arginine-rich domain that potentially play a role in viral RNA encapsidation during assem...

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mentioning

confidence: 99%

Structure of the hepatitis E virus-like particle suggests mechanisms for virus assembly and receptor binding

Guu

Liu

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

223

247

View full text Add to dashboard Cite

show abstract

“…F, forward; R, reverse. overlapping 30-mer synthetic peptides spanning 221-660 aa of the pORF2 and against 15 overlapping recombinant proteins, each of about 100 aa in size, spanning the full length of the pORF2 did not (29). These findings established for the first time that the HEV neutralization epitopes are conformation-dependent and locate between 452-617 aa of pORF2.…”

Section: Introductionmentioning

confidence: 80%

“…The antibodies elicited from pB166 could neutralize HEV strains of genotypes 1, 2 and 3 (29). HEV genotype 4 is newly identified in China and different from other genotypes in that its ORF2 product is 12 aa longer than that of other HEV isolates due to a single nucleotide insertion in the ORF2 region (19).…”

Section: Discussionmentioning

confidence: 99%

“…The mAb was isotyped IgG1 and purified using HiTrap protein G affinity columns (Pharmacia). The HEV neutralizing activity of 1G10 was determined by using an in vitro PCR-based neutralization assay as described previously (29,34). HEV inoculum NJ7 used for the in vitro neutralization assay was obtained from a fecal sample of a patient with acute hepatitis E and prepared as previously described (35).…”

Section: Methodsmentioning

confidence: 99%

“…After absorption for 2 h at 37C, the cells were washed with D-Hanks' solution three times followed by immediate RNA extraction with TRIzol reagent (Gibco BRL). Reverse transcription and nested PCR were conducted using a set of universal HEV PCR primers, generating a 236-nt fragment as previously described (29). A sense primer (5'-TCC CAT CAC CAT CTT CCA-3') and an anti-sense primer (5'-CAT CAC GCC ACA GTT TCC-3') were used to amplify glyceraldehyde-3-phosphate dehydrogenase (GAPDH) cDNA, generating a 390-nt fragment.…”

Section: Sds-page and Western Immunoblottingmentioning

confidence: 99%

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